Fluid powered device



S. N. ZILBERFARB FLUID POWERED DEVICE F eb. 25, 1964 Filed Dec. 22, 1961INVENTOR SAUL N. Z/LBEHFARB Y ATTORNEYS United States Patent O 3,122,045FLUID PGWERED DEVICE Saul N. Zilberfarb, Philadelphia, Pa., assignor -toSperry Rand Corporation, New York, NY., a corporation of Delaware FiledDec. 2J2, 1961, Ser. No. 161,494 11 Claims. (Cl. 83-590) The presentinvention relates to means for multiplying the effective force of afluid under pressure which is applied to a piston like member, and moreparticularly, to a new and improved card punching device.

Card punches of the prior art which have had wide application areoperated with solenoids, with the punches being staggered in a circle onlever arms. While this punch means is fairly reliable, it also entailsthe use of several parts linked so as to produce a mechanical advantagein order to achieve an effective punching force. Such mechanical linkageis subjected to wear and tear of its component parts due to bearingfriction, force moments, etc. The present invention obviates certain ofthe above disadvantages of the mechanical linkage by providing a directacting punch powered with a iluid under pressure, such as air or thelike. Only one moving part need be provided which is the punch pistonitself. Although iluid under relatively low pressure is employed as themotive force, a multiplication of this force is accomplished by means ofa novel configuration ofthe punch piston itself, Without need formaintaining close tolerances in fitting the punch piston within itshousing. If suicient piston travel is provided for, the width of theoverall piston may be almost equal to the punch width. Thus, the presentinvention results in a fluid powered punch which is relatively easy tofabricate without need for expensive machining or the like. For recordcard handling the overall piston width makes conventional multiplepunching feasible. The punch of the present invention is thereforeparticularly adapted for use in the rapidly expanding fluid dataprocessing art, wherein information is transmitted and processed via ailuid medium.

It is therefore an object of the present invention to provide a directacting punch powered with a fluid under pressure such as air.

It is another object of the present invention to provide a directacting'punch whose configuration allows the effective multiplication ofthe force produced by a fluid under relatively low pressure.

The manner in which the present invention accomplishes the abovedescribed function is to fabricate a punch piston having a plurality ofcircumferential grooves axially spaced along its length so as to form aplurality of surfaces which are essentially normal to the direction ofthe dynamic force applied by the actuating fluid pressure. The punch isloosely iitted within a cylindrical Vhousing such that there is suicientclearance between the outside punch diameter and the inside housingdiameter to allow the iluid to pass therebetween and exert its force oneach of the multiple ring surfaces formed by the grooves in the pistonbody. The provision of these multiple surfaces, in addition to the endsurface of the piston against which the fluid is also directed, therebyallows the effective multiplication of the force due to the kineticenergy of the iluid particles which pass with high velocity through theabove described clearance. Therefore, a relatively low fluid inputpressure can create sufficient force at the piston faces in ordertopuncture a conventional record card.

It is therefore another object of the present invention to provide acard punch comprised of a loose tting piston within a cylinder, wheresaid piston Vhas a plurality of axially spaced circumferential groovesfor effectively multiplying the force of a relatively low pressurefluid.

3,122,045 Patented Feb. 25, 1964 In addition to driving the punchthrough the card, means is provided in the present invention forretracting the punch from the card to hold it in readiness for asubsequent punch stroke. Although several different embodiments of theretracting means are disclosed, all of these utilize a uid stream underpressure, so that the present invention is completely compatible with apure fluid system.

Yet another object of the present invention is to therefore provide adirect acting punch powered with a fluid, said fluid also being used forretracting the punch from the card subsequent to the punch stroke.

Although the principle of the present invention is particularly adaptedfor use as a card punch and has therefore been specifically shown inthis environment, the scope of this invention is broader in that theprinciples here expounded can be utilized where there is desired theeffective multiplication of force exerted by a pressure fluid. Forexample, the grooved piston may be used to drive a crank shaft by means0f a connecting rod. Therefore, another object of the present inventionis to generally provide a cylinder and loose tting piston arrangementwherein effective multiplication of the force in a low pressure fluid isaccomplished by means of grooving in the piston body.

These and other objects of the present invention will become apparentduring the course of the following description with which the followingdrawings are to be used:

FIGURE l is a diagrammatic plan View of the invention as embodied in acard punch environment, which shows the punch and cylinder as well asthe actuating and retracting mechanism;

FIGURE 2 is a detailed sectional view of the punch cylinder and piston;

FIGURE 3 is a perspective View of the punch piston which emphasizes thearrangement of its circumferential grooves;

FIGURE 4 illustrates an alternative embodiment of the retractingmechanism; and

FIGURE 5 shows a third embodiment of the retracting mechanism.

FIGURE 1 is a diagrammatic view of the invention when used in a cardpunch environment. A punch chamber or cylinder 10 is provided withinwhich is loosely iitted a punch piston 11 having one end 12 brought to apoint for easy passage through a record card 13. When punch piston 11 isdirected upwards against card 13, point 12 pierces said card and entersthe opening 14 in die block 15. The actuating Huid under pressure enterscylinder 10 via a port 16 and is applied against the face of end surface17 of the punch piston, as well as leaking through the clearance formedbetween the outside piston diameter and the inside cylinder diameter t0impinge upon a plurality of circumferential grooves not shown in FIGURE1.

In this embodiment, the drive or punch stroke of piston 11 is in theupward direction against the force of gravity. After the punch point 12has perforated record card 13, the fluid entering port 16 is terminatedand an auxiliary fluid stream is forced into chamber lil via apassageway 18. The force of this fluid impinges upon piston 11 in thedownward direction so as to disengage point 12 from record card 13 andthereafter cause piston 11 to return to the bottom of cylinder 10adjacent port 16. yThe force of the fluid from passageway 1S need not belarge, inasmuch as it is aided by the force of gravity working againstpiston 11. Although not shown in FIGURE 1, since it does not comprise apart of the present invention, means are provided to move record card 13subsequent to a retraction stroke so as to present an unpuncturedsurface vto the punch position.

The hole placed into record card 13 by punch 11 may be interpreted in aVariety of ways, depending upon the particular code utilized in the dataprocessing system. Alternatively, the present invention may be utilizedin systems other than those processing information wherever it isdesired to punch a web of material.

The actuating fluid entering port 16 may be applied via a duct 19 fromone output of a typical pure -iiuid amplifier 2i). Amplifier 2@ normallycomprises a solid body having a plurality of fluid passageways throughwhich the working fluid may iow. This working fluid may be either air oranother gas, or water or another liquid. Although these fluidpassageways are shown invisible in the figure, it is to be understoodthat it is customary to mold or otherwise form the liuid passageways inone plastic laminate which is then covered on each side with solidplastic sheets so that the passageways are enclosed. A compressor orpump, not shown in FIGURE 1, supplies a suitable regulated stream offluid to the power input passageway 2l via a duct 22. The power streampasses through a restrictive orifice 23 and emerges into chamber 24 as ahigh velocity jet stream. Chamber' 24 is formed by the convergence ofleft output passageway 25 and right output passageway 26. The left wall27 and the right wall 28 of the chamber are set back from orifice 23and, in accordance with Bernoullis Principle, the high velocity jetissuing from orifice 23 creates regions of low pressure adjacent tothese walls. Within these regions of low pressure are layers of fluidwhich move at a much slower speed than the jet stream, hence theseregions are referred to as boundary layers. By properly designingchamber 24, these low pressure areas may be utilized to control the flowpath of the jet issuing from the orifice 23.

Two control signal input passages 29 and 3@ may be provided. Passage 29may be selectively provided with fluid via a duct 3l, with said fluidissuing from passage 29 into chamber 24 via an orifice 32 positioned vinwall 27. Passage 39 may be likewise selectively supplied with fluid viaduct 33, with this passage entering chamber 24 via an orifice 34 in wall2S. Both control streams are normally comprised of the same fluid asthat found in the power stream within passage 21.

In order to `direct the input power stream to that output connected withduct i9, a control stream is initiated from orifice 34 which breaks ordisperses a boundary layer and creates a condition of instability whichtends to push the power stream Iinto a direction away from wall 28. Asthe power stream is thus pushed to the left, it withdraws more and moremolecules of fluid from the region adjacent wall 27, thus creating a lowpressure region. The power stream thereupon moves into this low pressureregion and locks onto wall 27, with the result being that the powerstream now passes through passageway 25 to the duct 19 and into chamberl@ via port 16. At commencement of this operation, piston 11 begins tomove upwards so that it eventually strikes record card L13 and puncturessame.

Subsequent to the power stroke, the control stream lfrom orifice 34 isdiscontinued and the control stream from orice 32 commenced. Thiscontrol stream from orifice 32 thereupon shifts the power stream withinamplifier 20 so that it now exits from a second output thereof into theduct 35 which returns the fluid to the input of the pump. A smaller duct36 may be tapped from duct 35 so as to provide a resetting :liuid streamto passageway i8 for causing the retraction of punch piston 11 in themanner heretofore described.

'FIGURE 2. is a sectional View of the punch cylinder and piston whichclearly shows the novel configuration of the piston and the loose fitbetween it and the cylinder. Piston 11 is preferably sharpened at oneend 12 to enable its passage through record card 13. The diameter of theperipheral surface of piston 11 is less than the inner diameter ofcylinder 19, so that there .is a clearance therebetween which allows theinput fluid to leak along the longitudinal axis of the piston in themanner shown by the dotted lines. 'The greater portion of the pistonperipheral surface has multiple grooves 37 through 44 which may bemachined therein. Although eight such grooves have been shown axiallydisposed along the length of piston 1l in FlGURE 2, a lesser or `greaternumber may actually be provided. Each groove is delimited by twoparallel side walls, one of which is noted by the latter a. This sidewall of a groove is that which is normal to the path of the fluidleaking between the outside piston diameter and inside cylinderdiameter, such that the force exerted on said side wall due to thekinetic energy of the leakage liuid is in a direction tending to forcethe piston into record card f3.

The principle of operation of the present invention is believed to bethe following, Fluid is admitted by port le into chamber iti having arelatively low pressure on the order of live to thirty-live p.s.i.g.Ordinarily, if the punch piston were accurately fitted to the inside ofcylinder l@ so as to prevent huid leakage therebetween, the amount ofpressure required would be of considerable magnitude in order to createsufficient force at piston end surface ll7 to push through aconventional yrecord card. However, due to the loose lit of piston l1within cylinder 10, a portion of the fluid leaks between the pistonperipheral surface and the cylinder inside diameter at a relatively highvelocity `due to the small cross sectional area of this clearanceportion. As this high velocity iiuid passes down aiong the longitudinalaxis of the piston, it expands into each of the multiple grooves andapplies a force against the wall surface a to this high velocity leakagefluid effectively multiplies its force which is enough to drive thepiston point 12 through the record card. With these multiple grooves anda sharpened punch, punching is made feasible even though the piston isnot accurately fitted within cylinder 10. Therefore, ince there is noneed for a close tolerance between the piston outside `diameter and thecylinder linside diameter, fabrication of the punch arrangement isextremely simple and cheaper than that of the prior art. Indeed, it isideally desirable to have the punch occupy a space which is close to theinside diameter of the containing cylinder, but not so close as toseriously effect the iluid velocity of the leakage iiuid. With theconfiguration shown, no O-rings or lubricants are required.

lt is to be emphasized, too, that the multiplication of force in thepiston-cylinder arrangement of FGURE 2 is not caused by the staticpressure of the entering fluid. `Instead, it is due to the kineticenergy of the high Velocity leakage fluid. Since this leakage uid isdirected toward record card 13, it initially applies a force onlyagainst surface a of a groove as it expands into the volume of thegroove. In this case, it never applies any substantial force against theopposite side wall of the groove which, if present, would tend tomaintain the piston in its retracted position. Therefore, the multiplegrooved piston is acted upon by the dynamic energy of moving iiuidparticles, at least as regards the force applied to walls a of thegrooves. With respect to the end surface 17 of the piston il, the forcethere applied may be due to both static and dynamic pressures.

As before described in connection with FIGURE l, a passageway 18 isprovided in the wall of cylinder l) through which a fluid stream travelsto impinge upon the punch piston in order to effect the retractionthereof subsequent to the punch stroke. As more clearly shown in FIGURE2, passageway i8 enters the chamber at an angle so lthat the fluidVstream exerts a downward force on the punch piston opposite to thedirection taken by the piston during its punch stroke. If the punch 11is placed below record card 13, as is the case in the preferredembodiment of the invention, then the force exerted by the retractingtluid stream from passageway 18 need only be great enough to overcomethe friction of the record card upon end 12 of the piston so as todisengage same from the card. However, punch cylinder may be lplaced ontop of the record card if desired, with due changes being made in theforce of the retracting stream.

FIGURE 4 is an alternative embodiment of the retracting means whereinpassageway 18 is no longer provided in the wall of cylinder 10. Instead,the opening 14 in die block is elongated into a passageway at theopposite end of which is provided a fluid input via duct 36 fromV theappropriate output of the fluid amplifier shown in FIGURE l. If thescheme of FIGURE 4 is utilized, then the retracting lluid stream cannotimpinge upon the punch piston until point 12 punctures the record cardand exposes itself to the retractive lluid stream which enterspassageway 14 in the die block. Although the retracting lluid may besupplied to conduit 36 by the fluid amplier as shown in FIGURE l, i.e.,at only a certain period of time during the punch cycle, an alternativemode of operation of FIGURE 4 is as follows: A source of fluid may beapplied to passageway 14 which is main tained even during the punchstroke. As long as there is no perforation in record card 13, then thislluid in passageway 14 cannot effect the motion of the punch piston incylinder 10. However, as soon as the sharpened punch point 12 passesthrough the record card and enters passageway 14, it is immediatelyexposed to the lluid pressure therein which thereupon forces the pistonto return to its original retracted position. Upon termination of thefluid entering port 16, record card 13 is then moved so as to remove thenewly punched hole from alignment with passage 14 and cylinder 10. Theeffect of the retracting lluid in passageway 14 is thereby blocked by anunpunched portion of record card 13. Continual lluid llow at conduit 36causes faster retraction of the punch than if flow at conduit 36 wereinitiated only after termination of llow at port 16.

FIGURE 5 shows still another embodiment of fluid retracting mechanismwhich may be used in conjunction with the present invention. Retractionof piston 11 is here caused by the creation of a suction force in theend of the cylinder opposite that adjacent record card 13. This force iscreated by a stream of fluid entering this cylinder end via an inputconduit 40 and exiting through a conduit 41 in the direction of thearrows. Inserted within conduit 4i) is a conventional ball and checkvalvel 42 which serves to prevent fluid flow in the conduit in adirection opposite to that indicated by the arrow.

Also constructed within this cylinder end is a guided ball check valvecomprised of a ball 43 positioned in a guide or race way 44 so that saidball is movable to block either port 16 or port 45, the latter providingthe outlet from the cylinder to conduit 41. When the power stream llowsthrough conduit 19 and enters cylinder 10 via port 16, ball 43 is movedto block port 45 and so prevent exit of said power stream therefrom. Theball and check valve 42 in conduit 4@ likewise prevents any portion ofthe power stream from escaping from cylinder through port 46. Thus, thepower stream is applied against piston 11 and drives same through therecord card in the manner previously described. Upon cessation of thepower stream through port 16, ball 43 returns to block port 16 eitherthrough the force of gravity (in the event that the piston is drivenupwards) or by a spring which may be attached between the inner wall ofcylinder 10 and ball 43 in order to retain the latter at port 16 in theabsence of power stream flow in conduit 19. Thereafter, fluid ilow isinitiated in conduit 40 which enters cylinder 10 and exits therefrom viaconduit 41 since port 45 is no longer blocked by ball 43. The transverseflow of fluid in cylinder 10 lowers the pressure so as to exert asuction force against piston 11 to thereby return it to its retractedposition in preparation for the next subsequent power stroke.

Fluid llow in conduit 42 may also be used to maintain piston 11 in itsretracted position in the event that the punch cylinder 10 is notvertically arranged to utilize the force of gravity for this function.Alternatively, the arrangement shown in FIGURE 5 may be used incombination with the arrangements in FIGURES 2 or 4. For example, fluidin conduit 36 of FIGURE 2 might be used to effect the retraction of thepunch, and fluid through conduit 42 might thereafter be used to maintainand hold the punch in its retracted position. Therefore, depending uponthe particular environment in which the invention nds itself, theretracting mechanisms shown in FIGURES 2, 4, and 5 may either be usedsingly or in combination with one another.

Although the present invention has been described in connection with acard punch, it is to be observed that the loose fitting multiple groovepiston may be employed to perform work other than that of punching holesin web like material. Furthermore, when used in a card punchenvironment, the punch cylinder may be placed above the record cardinstead of below, so that the force of gravity upon the punch piston isused to assist the actuating tluid pressure during the punch stroke. Insuch a situation, the retracting fluid stream must have a somewhatgreater force in order to raise the punch piston and maintain same inits retracting position. Horizontal arrangements of cylinder 10 may beutilized. It is there# fore apparent that many modifications andalterations may be made by one skilled in the art without departing fromthe spirit of the invention as defined in the appended claims.

I claim:

1. Apparatus for converting lluid pressure into mechanical motion whichcomprises: an elongated chamber having one end adapted to admit a fluidunder pressure, and a piston slidably located within said chamber andloosely fitted therewith to provide a clearance between its peripheralsurface and said chamber which has a cross-sectional area to permitfluid flow from said chamber one end to be substantially maintainedtherethrough in the direction of the chamber opposite end at relativelyhigh velocity for the entire axial length of at least a portion of saidpiston peripheral surface, where said piston peripheral surface portionhas formed therein at least one circumferential groove into which aportion of said clearance lluid enters to strike its interior in adirection towards said chamber opposite end at relatively high velocityand thereby continuously apply an unbalanced dynamic force to saidpiston in the direction of said chamber opposite end for the duration oflluid admission to said chamber one end.

2. Apparatus for converting fluid pressure into mechanical motion whichcomprises: an elongated chamber having one end adapted to admit lluidunder pressure, and a piston slidably located within said chamber andloosely fitted therewith to provide a clearance between its peripheralsurface and said chamber which has a cross-sectional area to permitfluid flow from said chamber one end to be substantially maintainedtherethrough in the direction of the chamber opposite end at relativelyhigh velocity for the entire axial length of at least a portion of saidpiston peripheral surface, where said piston peripheral surface portionhas formed therein a plurality of axially spaced circumferential groovesinto each of which a portion of said clearance iluid enters to strikeits interior in a direction towards said chamber opposite end atrelatively high velocity and thereby continuously apply anunbalanceddynamic force to said piston in the direction of said chamber oppositeend for the duration of fluid admission to said chamber one end.

3. Apparatus according to claimY 2 wherein said piston has at least fourcircumferential grooves.

4. Fluid powered punch apparatus comprising: an elongated chamber havingone end adapted to admit fluid under pressure for driving a punch bodyand the other end adapted to expose the material to be punched to thedriven punch body, a piston like punch body slidably located within saidchamber and loosely fitted therewith to provide a clearance between itsperipheral surface and said chamber which has a cross-sectional area topermit fluid flow from said chamber one end to be substantiallymaintained therethrough in the direction of the chamber other end atrelatively high velocity for the entire axial length of at least aportion of said punch body peripheral surface, and means for retractingsaid punch body subsequent to the punch operation, where said punch bodyperipheral surface portion has formed therein at least onecircumferential groove into which a portion of said clearance fluidenters to strike its interior in a direction towards said chamberopposite end at relatively high Velocity and thereby continuously applyan unbalanced dynamic force to said punch body in the direction of saidchamber other end for the duration of fluid admission to said chamberone end.

5. Fluid powered punch apparatus comprising: an elongated chamber havingone end adapted to admit uid under pressure for driving a punch body andthe other end adapted to expose the material to be punched to the drivenpunch body, a pistol like punch body slidably located within saidchamber and loosely fitted therewith to provide a clearance between itsperipheral surface and said chamber which has a cross-sectional area topermit fluid ilow from said chamber one end to be substantiallymaintained therethrough in the direction of the chamber other end atrelatively high velocity for the entire axial length of at least aportion of said punch body peripheral surface, and means for retractingsaid punch body subsequent to the punch operation, where said punch bodyperipheral surface portion has formed therein a plurality of axiallyspaced circumferential grooves into each of which a portion of saidclearance iiuid enters to strike its interior in a direction towardssaid chamber opposite end at relatively high Velocity and therebycontinuously apply an unbalanced dynamic force to said punch body in thedirection of said chamber other end for the duration of fluid admissionto said chamber one end.

6. Apparatus according to claim 5 wherein said punch body has at leastfour circumferential grooves.

7. Apparatus according to claim 5 wherein said retracting meanscomprises an orifice in the wall of said chamber positioned near saidother end which is adapted to receive fluid for directing same againstsaid punch body to eiect retraction thereof.

8. Apparatus according to claim 5 wherein said retracting meanscomprises a nozzle positioned opposite said chamber other end, betweenwhich two elements the material to be punched passes, where said nozzleis adapted to receive Huid for directing same against said punched bodywhenever the latter is exposed thereto in order to effect retractionthereof.

9. Fluid powered punch apparatus comprising: an elongated chamber havingone end adapted to admit fluid under pressure for driving a punch bodyand the other end adapted to expose the material to be punched to thedriven punch body, a piston-like punch body slidably located within saidchamber and loosely fitted therewith to provide a clearance between itsperipheral surface and said chamber which has a cross-sectional area topermit fluid flow from said chamber one end t0 be substantiallymaintained therethrough in the direction of the chamber other end atrelatively high velocity for the entire axial length of at least aportion of said punch body peripheral surface, and means for creating asuction force at said chamber one end to retract said punch bodysubsequent to the punch operation, where said punch body peripheralsurface portion has formed therein a plurality of axially spacedcircumferential grooves into each of which a portion of said clearanceliuid enters to strike its interior in a direction towards said chamberopposite end at relatively high velocity and thereby continuously applyan unbalanced dynamic force to said piston in the direction of saidchamber other end for the duration of iiuid admission to said chamberone end.

10. Apparatus according to claim 9 wherein said retracting meanscomprises means to introduce a transverse tluid ow in said chamber oneend to thereby create the suction force for retracting said punch body.

11. Apparatus according to claim 10 wherein said punch body has at leastfour circumferential grooves.

References Cited in the file of this patent UNITED STATES PATENTS532,265 Cornell Jan. 8, 1895 1,754,625 Henning Apr. l5, 1930 2,833,602Bayer May 6, 1958 2,954,755 Pecchenino Oct. 4, 1960 FOREIGN PATENTS472,999 Great Britain Oct. 4, 1937

1. APPARATUS FOR CONVERTING FLUID PRESSURE INTO MECHANICAL MOTION WHICHCOMPRISES: AN ELONGATED CHAMBER HAVING ONE END ADAPTED TO ADMIT A FLUIDUNDER PRESSURE, AND A PISTON SLIDABLY LOCATED WITHIN SAID CHAMBER ANDLOOSELY FITTED THEREWITH TO PROVIDE A CLEARANCE BETWEEN ITS PERIPHERALSURFACE AND SAID CHAMBER WHICH HAS A CROSS-SECTIONAL AREA TO PERMITFLUID FLOW FROM SAID CHAMBER ONE END TO BE SUBSTANTIALLY MAINTAINEDTHERETHROUGH IN THE DIRECTION OF THE CHAMBER OPPOSITE END AT RELATIVELYHIGH VELOCITY FOR THE ENTIRE AXIAL LENGTH OF AT LEAST A PORTION OF SAIDPISTON PERIPHERAL SURFACE, WHERE SAID PISTON PERIPHERAL SURFACE PORTIONHAS FORMED THEREIN AT LEAST ONE CIRCUMFERENTIAL GROOVE INTO WHICH APORTION OF SAID CLEARANCE FLUID ENTERS TO STRIKE ITS INTERIOR IN ADIRECTION TOWARDS SAID CHAMBER OPPOSITE END AT RELATIVELY HIGH VELOCITYAND THEREBY CONTINUOUSLY APPLY AN UNBALANCED DYNAMIC FORCE TO SAIDPISTON IN THE DIRECTION OF SAID CHAMBER OPPOSITE END FOR THE DURATION OFFLUID ADMISSION TO SAID CHAMBER ONE END.